Since 1976, researchers in the Language in the Aging Brain project have been studying language changes in normal aging. We have found, as have others, that certain language abilities are maintained, or even improve, with age (e.g. vocabulary), while other language abilities decline with age (e.g. lexical retrieval, auditory comprehension of complex material). In the current grant cycle we have been seeking to explain these age-related changes in language, primarily evaluating the degree to which other cognitive changes of aging may contribute to alterations in language function. For the new proposal we have developed a complex model of language change with aging wherein vascular health factors, as well as cognitive factors, play a role. We shall test the following hypothesis: Age-related decline in specific language functions is mediated by changes in executive functions associated with declining vascular health. To test this hypothesis we shall 1) focus on lexical retrieval and auditory comprehension--language domains that we know to decline in healthy older adults; 2) expand our sample to include a new group of longitudinal participants to cross validate our original longitudinal findings and expand the diversity of our sample in terms of health, socioeconomic status, and ethnicity; 3) incorporate a well-studied longitudinal sample of older adults from the VA Normative Aging Study; 4) test the following specific set of predictions, derived from our model: (A) cerebrovascular disease risk factors in aging are linked to frontal system changes that, in turn, have negative effects on executive function; (B) this decline in executive function will exert a negative effect on lexical retrieval and auditory comprehension. Our theoretical framework for language in aging hypothesizes a relationship among three sets of components (language abilities, cognitive abilities, health), each component measured by constructs, each construct measured by multiple indicators. Successful completion of this project will move the field of cognitive neuroscience closer to a more complete explanation.